[Initiative] Stable Catalog Resource Identity and Rename-Aware UID Lifecycle

[juliuskrah]

Summary

Introduce stable resource identity for catalog objects so logical moves (renames) preserve identity while delete/recreate produces a new identity. The Sync Controller must manage identity independently of filename churn in Git.

In Scope

• Add a persistent identity mapping in ScyllaDB keyed by (kind, namespace, name) with value uid (UUID v4)
• Implement rename-aware reconciliation in the Sync Controller using Git rename detection (git diff -M semantics)
• Preserve uid when a file is moved/renamed but still represents the same logical object
• Remove mapping entries when resources are deleted
• Generate a new uid when a previously deleted (kind, namespace, name) is re-added
• Add observability for identity decisions (create, rename-preserve, delete, recreate)

Out of Scope

• Repository-level storage identity/path strategy (already tracked elsewhere)
• Authorization policy changes
• UI changes

Acceptance Criteria

• A durable mapping table exists for resource identity resolution in ScyllaDB
• Reconcile logic preserves uid for rename-only diffs
• Reconcile logic allocates new uid for delete/re-add lifecycle
• Delete events remove identity mappings deterministically
• Integration tests cover: edit, rename, delete/re-add, and concurrent controller runs
• API responses and internal events surface stable uid consistently

Implementation Notes

Resource identity must be independent from path identity. Git paths are mutable and user-facing; uid is immutable and system-facing. Without this separation, downstream references and audit trails become unstable whenever files are renamed. Rename-aware reconciliation keeps continuity for humans while preserving strict object lifecycle guarantees needed for API consumers and controllers.

Dependencies

• Depends on: [Initiative] Datastore Backend: ScyllaDB with Migrations #102 (ScyllaDB backend)
• Related: [Initiative] Controller Watch API with resourceVersion Resume #131 (Watch API / resourceVersion resume), [Initiative] Tag-Gated Sync Controller for Atomic Release Promotion #132 (tag-gated sync controller), [Initiative] Kubernetes-style Catalog Frontmatter #40 (Kubernetes-style catalog frontmatter)